The present invention relates to photographic apparatus and, in a preferred embodiment, to photographic cameras having a light-sensitive element and a capacitor which together constitute a timing circuit. The timing circuit is connected to terminating means which generally include a bistable stage which, when in a first state causes an electromagnet to hold open the shutter and when in a second state causes the electromagnet to terminate the exposure.
In general, photographic cameras operate at different exposure factors. For example the sensitivity of different films differs. Each such sensitivity would herein be referred to as an exposure factor. Similarly, the aperture values change. Each such aperture value would herein also be referred to as an exposure factor. In known photographic apparatus the difference in exposure factors is taken into account by the extent in which the light-sensitive element is protected from light by, for example, a gray wedge or an auxiliary diaphragm. However this results in the difficulty in that the sensitivity of the light-sensitive element decreases when increasing portions thereof are covered. This results in an increase in its inertia and therefore in errors in the exposure time.
A further known method of changing the timing circuit in order to accommodate different exposure factors is to change the capacitance of the timing capacitor. This of course has the disadvantage that, for each exposure factor, a capacitor must be provided. However increasing the number of capacitors results in an increase of the size, weight and cost of the camera.